Cal. Health and Safety Code § 112160

(a) The director may declare any area within the jurisdiction of this state to be a closed area if it is determined that shellfish taken from the growing area may be unsafe or unfit for human consumption. (b) The director shall close to the taking of shellfish for a period deemed advisable any waters to which shellfish from a closed area may have been transferred. (c) The director shall establish by order the areas that he or she declares unsafe or unfit for shellfish harvesting and shall modify or revoke the order in accordance with the results of chemical, toxicologic, and bacteriological surveys conducted by the department. The director shall file the order in the office of the department, and shall furnish copies of the orders describing closed areas to the Department of Fish and Game, the State Water Resources Control Board, and to any interested person without charge. (d) Prior to the director’s declaration that shellfish-growing waters may be unsafe and shellfish grown in these waters may not be taken for human consumption, the department shall do all of the following: (1) Give at least 20 days’ notice of its intended action. The notice shall include a statement of either the terms or substance of the intended action or a description of the subject and issues involved, and the time when, the place where, and the manner in which, interested persons may present their views thereon. (2) Afford all interested persons reasonable opportunity to submit data, views, or arguments orally or in writing. The department shall consider fully all written and oral submissions respecting the proposed action. (e) If the department finds that the shellfish harvested from an area is unsafe or unfit for human consumption and states in writing its reasons for that finding, it may proceed without prior notice or hearing to take emergency action. The action may be effective for a period of not longer than 30 days, during which time the department shall initiate the procedures contained in subdivision (d).